An embodiment relates generally to external device integration within a vehicle.
Determining a state-of-charge (SOC) for a battery can be performed utilizing various techniques utilizing coulomb counting or parameter estimations techniques. Coulomb counting involves the use of one measurement (i.e., battery current) to estimate the battery state-of-charge. The accuracy of the battery current is critical to determining a state-of-charge. If there is measurement error, such as the current sensor not accurate integration error accumulates quickly. Furthermore, the coulomb counting is not carried out during the vehicle ignition off in order to save battery energy, which may bring additional SOC estimation error. Most vehicles utilize low end current and voltage sensors which do not provide accurate results. Therefore, many systems utilize high cost current sensors to monitor SOC all the time to overcome this deficiency.